r161856, bootstrapped with --enable-build-with-cxx, fails the bootstrap comparison on i386.o. By doing a binary search applying the first patch for PR44512 http://gcc.gnu.org/ml/gcc-patches/2010-06/msg01765.html to older revisions, I found that the onset of these comparison failures is between revision 161800 and 161802. As 161801 was a fortran-only patch, 161802 seems the likely culprit.
-- Summary: --enable-build-with-cxx Bootstrap comparison failure Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: bootstrap AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: amylaar at gcc dot gnu dot org GCC host triplet: i686-pc-linux-gnu OtherBugsDependingO 44433 nThis: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44832